A conceptual model of the influence of stress on female reproduction

Intriguingly, similar neurotransmitters and nuclei within the hypothalamus control stress and reproduction. GnRH neurone recruitment and activity is regulated by a balance between stimulation, suppression and permissiveness controlled by noradrenaline, neuropeptide Y and serotonin from the brain stem, impact from glutamate in the medial preoptic area and neuropeptide Y in the arcuate nucleus, in opposition to the restraining influences of -aminobenzoic acid within the medial preoptic area and opioids from the arcuate nucleus. Stress also activates neuropeptide Y perikarya in the arcuate nucleus and brain stem noradrenaline neurones. The latter project either indirectly, via the medial preoptic area, or directly to the paraventricular nucleus to release corticotrophin releasing hormone (CRH) and arginine vasopressin (AVP). Within the medial preoptic area, GnRH neurones synapse with CRH and AVP axons. Stimulation of CRH neurones in the paraventricular nucleus also activates -aminobenzoic acid and opioid neurones in the medial preoptic area and reduces GnRH cell recruitment, thereby decreasing GnRH pulse frequency. Oestradiol enhances stress-induced noradrenaline suppression of LH pulse frequency but when applied in the paraventricular nucleus or brain stem, and no